1. Field of the Invention
The present invention relates generally to aircraft stores, and more specifically to a system and method for attaching or interfacing a targeting pod or weapon to different types of host aircraft and aircraft variants using object oriented software.
2. Description of the Related Art
A targeting pod is a device designed for attachment to an aircraft such as a fighter aircraft. Modern targeting pods include high-resolution FLIR devices, dual-mode lasers, CCD-TV, laser spot trackers and laser markers. Targeting pods are designed to detect and identify enemy targets, and provide pointing and range information to the aircraft's weaponry. Targeting pods usually provide automatic tracking and laser designation of targets, and they often provide real-time imagery that is presented on cockpit displays.
A targeting pod, such as the SNIPER XR (eXtended Range), developed by Lockheed Martin, is one of the advanced targeting pods used by the US Air Force on various host aircraft and variants. A host aircraft is generally considered to be a family of aircraft such as the F-16. A variant is considered to be a different version of the same family. For example, an F16 host may contain the following variants: BLK30 SCU5, BLK50 M3+, BLK50 M4 and BLK40 T7. An F15 host also supports a suite of variants, SUITE5 and SUITE4. The SNIPER currently supports eight different host aircraft variants (F16-4 versions, F15-2 versions, A10 and F18 in a single Operation Flight Program (“OFP”)). By definition, each variant exhibits a unique signature that can be distinguished by either static protocol or dynamic characteristic. Static protocol is primarily used as the detection discriminator. Typically each interface has a uniquely defined data set (number of messages, size, etc.) that can be queried at instantiation. Some variants are not uniquely defined by static protocol. These variants use data characteristic as a secondary discriminate. A data characteristic can be an observed behavior of an individual data item, such as time tag rollover. Since there are a plurality of different host aircraft and variants, it is often difficult to attach or to interface a targeting pod to more than one type of host aircraft or variant.
Legacy targeting pod systems include LANTIRN, designed by Lockheed Martin, ATFLIR designed by Raytheon and LITENING designed by Northrop Grumman. The known solutions for attaching legacy systems to different host aircraft include “hardware jumpers” or dip switches to identify and detect a unique host. Other approaches have been to “hard code” a variant to only operate on a specific host/variant and not dynamically determine the host/variant. These legacy systems include the disadvantage of needing hardware to either convert a protocol or uniquely identify a host. They may also need to change hardware components or reprogram and the targeting pod or “asset” cannot be quickly moved from host to host which is known as “asset pooling”. The legacy systems also cannot provide individualized host compatibility without some form of separate specialized software objects and/or hardware adaptation, and there is an increased product cost resulting from the need for a hardware identifier or individually developed and maintained software objects which are adapted for use with a network protocol, such as the 1553 protocol used by the U.S. military.
MIL-STD-1553 is a military standard that defines a local area network (LAN) originally developed for military aircraft. It is a digital time-division multiplexing network protocol, and it is used when fast, positive control is required. The standard defines the handshaking, data formats and timing requirements of the protocol as well as the electrical characteristics of the bus and the interface electronics of various terminals.
In the military standard, one terminal is designated as the bus controller; and all others are remote terminals each having a specific terminal address. All transmissions are initiated by the bus controller by transmitting a command word. Encoded into the command word are a terminal address, a TR (transmit/receive) bit, a subaddress and a word count. Remote terminals monitor the bus and respond only to commands containing its own terminal address. The remote terminal transmits or receives the specified number of words from/to the specified subaddress. A remote terminal transmits a status word that includes its terminal address before transmitting data words or to confirm reception of data words. Special messages are reserved for broadcast data and mode codes. Words are 16 bits long and are transmitted at one megabit per second. Messages can have up to 32 words.
Targeting pods must exchange application specific messages with the host aircraft, and the messages must be translated for use with the targeting pod software. Targeting pods such as SNIPER have core capabilities that may account for ˜95% of the embedded software functionality. The core represents the union of shared targeting capabilities available to any host. Only 5% of the OFP software associated with the SNIPER is dedicated to a unique host and host variant implementations.
In order to exploit the core capabilities of targeting pods, legacy systems have utilized multiple, non-resident software executables to support the interface to multiple host implementations. These legacy solutions are disadvantageous because they require use of multiple embedded OFPs to support all host variants. They increase the cost to develop and integrate new host variants, and they greatly increase the customer's cost of maintaining multiple versions of fielded pods. Lastly, the legacy systems prevent easy migration of core capabilities to future interface protocols, such as Ethernet or Open Systems, without having a shared translation layer from which protocol differences can be transversed.
Accordingly, there is a need for a targeting pod system and method that operates seamlessly with multiple hosts and host variants utilizing a common physical interface protocol to provide host detection, isolation and translation. There is also a need to eliminate hardware signals for host detection and to eliminate multiple OFP executables for interface with variant host applications. There is a need for a targeting pod system and method that will allow for effective asset pooling and reduced costs.